This invention relates to innovations and improvements in axle suspensions for trucks and trailers and in certain component parts of such suspensions. More particularly, the invention relates to such suspensions wherein a leaf spring, such as a single-leaf leaf spring, has an eye formation at its proximal end by which it is pivotally connected to a hanger on its proximal side of a chassis side rail or frame member while the distal end portion of the leaf spring is connected to a hanger on the opposing side of the frame member by a new and improved attachment part. The new and improved attachment part permits play or movement of the distal end portion of the leaf spring about its natural instant center of rotation produced by the fore-and-aft movement of the spring and its angle of rotation due to deflection. At the same time, the new and improved attachment part anchors the distal end portion of the leaf spring to its associated frame hanger in the event the pivotal connection at the proximal end becomes broken or unattached. Intermediate its opposite ends, the leaf spring is mounted on the adjacent end of the axle and it optionally supports an air cushion or air bag which may provide a substantial portion of the support for the chassis.
One advantage of the suspension of this invention is the omission of an additional leaf having a so-called "military wrap" formation that embraces the spring eye end of the leaf spring. This omission is permissible since, even with the spring eye freed or detached from its frame hanger, the opposite end of the single-leaf leaf spring is connected to its associated frame hanger in a sufficiently secure manner so that the end of the axle on which the leaf spring is mounted will not become loose and/or uncontrolled while the vehicle is brought to a safe stop.
In view of the foregoing, it is a principal object of the present invention to provide a novel component part of a suspension system whereby the movement of the distal end portion of the leaf spring on which it is mounted is permitted to pivot about its natural instant center of rotation during jounce and rebound of the axle on which the leaf spring is mounted.
It is another object of the present invention to provide an attachment part that creates a single point of rotation for the distal end portion of a leaf spring during jounce and rebound of the axle on which the leaf spring is mounted.
It is a further object of the present invention to provide a novel component part of a suspension system which eliminates the spring pin or slipper surface wear associated with those leaf springs having a fore-and-aft extending bearing or contact surface.
It is a further object of the present invention to provide a novel component part of a suspension system which mounts to a leaf spring.
It is yet another object of the present invention to provide a novel component part of a suspension system which serves as an additional safety mechanism for a leaf spring.
It is yet another object of the present invention to provide a novel component part of a suspension system which enables the leaf spring on which it is mounted to be free of a military wrap.
It is still another object of the present invention to provide a novel component part of a suspension system which enables the system to include a single-leaf leaf spring on each side of the vehicle for supporting that side of the vehicle axle.
It is yet another object of the present invention to provide a novel component part of a suspension system which enables the suspension system to comprise a lighter-weight suspension system.
It is finally another object of the present invention to provide a novel component part of a suspension system which reduces the manufacturing and maintenance costs of the system by eliminating the need for otherwise necessary parts and points of rotation thereof.
These and other objects of the invention will be apparent to those skilled in the art from the following detailed description of the preferred embodiment taken in conjunction with the accompanying drawings wherein: